Aeronautical flight is a complicated orchestra of engineering requiring considerations of lift, drag, aerodynamics, electrical engineering, electronics, hydraulic controls, material choices, dynamic control, weather, environmental control, and a variety of other issues. Safety, however, is a paramount goal of all flight solutions. Innumerable mechanism on board private and commercial airplanes are in place for safety reasons primary or solely.
As an airplane travels through the air, static electricity can build on the airplane. This static electricity is created by friction between the airplane body, or “skin,” and the rapid movement of air particles across that skin, much in the same way that static electricity is created by dragging one's shoes across a carpet. The electrical static normally produced during a flight is increased when the airplane flies through rain, snow, sleet, ice, or dust. Such precipitation is known as “p-static.” P-static is dangerous because it reaches levels of charge high enough to affect internal electronic controls and radio operations in the airplane. Pilots can hear the effects of p-static as high-pitched whining or popping over their radio systems. When p-static reaches high enough levels, it discharges from the airplane, and in doing so, can damage the airplanes electronic and radio components. In extreme cases, p-static can destroy electronic or radio components.
Static wicks have been used for over half a century to dissipate static electricity, and p-static in particular, consistently and rapidly, to prevent the buildup of dangerous levels of static electricity on the airplane. Static wicks are electrical components typically installed on the trailing edges of the plane, such as on the wings, ailerons, and tails. Static electricity on the plane moves across the plane body to the static wick where it can be let off, or discharged, into the air safely.
Static wicks are effective at discharging static electricity when operating properly. However, like most equipment, static wicks often require replacing. Typically, there will be a dozen or so static wicks distributed across the airplane. If one or several of the static wicks is or becomes inoperable during flight, static electricity can build do unsafe levels. It is difficult, however, to determine whether a static wick is operating properly. Typically, testing the operational status of a static wick requires a technician to remove the static wick from the airplane and take it to a bench for testing with a power supply and multimeter. This process can take hours. If several static wicks have to be tested, the testing process can be extremely lengthy, resulting in increased operational costs. An improved way to determine the operational status of a static wick is needed.